Molina trained in the Barça Juniors Luján sports project, aFC Barcelona project inArgentina,[3] which even led him to travel toBarcelona to train with the lower sections of FC Barcelona. In 2012, the Juniors Luján project was integrated into the youth ranks ofCA Boca Juniors, and Molina continued his training in this club.[4]
On 18 February 2016, he made his first team debut for Boca Juniors in a league game againstSan Martín de San Juan, playing the full game.[5][6] In January 2018, Molina was loaned out toDefensa y Justicia for the rest of the year.[7]
On 15 September 2020, Molina joinedUdinese Calcio on a free transfer until 2025.[8] On 28 July 2022, he joinedAtlético Madrid on a five-year contract,[9] for a reported fee of €10 million and €5 million in variables.[10]
In the2022 FIFA World Cup quarter-final match against theNetherlands on 9 December 2022, Molina scored his first goal for Argentina, starting in six matches for Argentina as first choice right back scoring one goal and providing one assist throughout the tournament en route to become champions.[12]
In June 2024, Molina was included in Lionel Scaloni's final 26-man Argentina squad for the2024 Copa América.[13]